Grinding separation method for micro-fine particle lead-zinc ore

Abstract

The invention relates to a grinding separation method for micro-fine particle lead zinc ore. The grinding separation method for the micro-fine particle lead-zinc ore comprises the following steps that S1, fine grinding is conducted again; s2, size mixing and dosing; s3, primary fine selection; s4, adding chemicals again; and S5, secondary fine selection. According to the scheme provided by the invention, the advantages that fine grinding is realized through selective ore grinding of the moxa sand mill and the micro-bubble jet flotation machine is suitable for fine-grain ore separation are fully utilized, and the problems that conventional ore grinding and fine grinding are difficult and conventional flotation fine grains are difficult to float are solved; the fine grinding and fine separation technological process has the advantages of being environmentally friendly, high in separation efficiency, low in grinding and separation cost, high in adaptability to ore property fluctuation and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lead-zinc sulfide ore dressing, and in particular to a grinding and separation method for micro-fine-grained lead-zinc ore. BACKGROUND

[0002] In the related art, the process mineralogy of the raw ore shows that the raw ore contains 3.54% galena, 8.89% sphalerite and 4.32% pyrite, and the main gangue minerals are 33.90% quartz, 25.65% calcite, 15.26% mica and 4.45% feldspar, etc. The embedded particle size characteristics of the target mineral galena are as follows: most of the galena is mixedly distributed with the pyrite, or is intergrown or wrapped with the sphalerite, the pyrite and arsenopyrite, and the embedded particle size is between 0.05 mm and 10 mm; a small amount of the galena is fine, and is wrapped in transparent minerals, and the embedded particle size is between 0.005 mm and 0.05 mm; due to the fine particle size, the part of the galena is difficult to dissociate. The sphalerite is irregularly granular, and the embedded characteristics are as follows: part of the sphalerite is intergrown with the galena and the pyrite; part of the sphalerite is wrapped with the galena and the pyrite; a small amount of the sphalerite is distributed between the transparent minerals or is in the form of a vein, and is filled along the rock fissure; the sphalerite and the pyrite are occasionally in the form of a spherulite, and are intergrown with the arsenopyrite; and the embedded particle size is between 0.01 mm and 2 mm, and part of the fine-grained sphalerite is difficult to dissociate.

[0003] In the grinding and separation process of the lead-zinc sulfide ore, a ball mill is mainly used for ore grinding, and an aerated or self-suction mechanical stirring flotation machine is mainly used for flotation. Due to the different embedded particle sizes of the target minerals such as the galena and the sphalerite in the raw ore, the lead-zinc ore with simple and coarse embedded particles is generally subjected to one-stage grinding, and the fineness of-200 mesh is 50-75% to realize the flotation separation; for the lead-zinc ore with fine and complex embedded particles, in order to save energy consumption and reagent consumption, one-stage coarse grinding is usually adopted, the fineness of-200 mesh is 50-70%, the lead-zinc liberation degree is 70-80%, and the preferential flotation or the bulk flotation is carried out; the coarse concentrate is subjected to regrinding, the grinding product reaches the appropriate fineness, the fineness of-500 mesh is generally controlled to be not more than 75%, the target mineral liberation degree reaches 85-90%, and then the cleaning separation is carried out. In the grinding and separation process, both the high liberation degree and the control of the grinding fineness to avoid over-pulverization and mudification to cause the difficulty in the flotation recovery need to be realized.

[0004] The above grinding and separation process is suitable for most mines, but for the lead-zinc ore with fine and complex embedded particles, it is difficult to effectively separate the lead and the zinc by using the conventional process, and the following problems exist: (1) the target mineral liberation degree of the grinding product is low, and the over-pulverization is serious; (2) the conventional flotation machine is difficult to separate the lead and the zinc when the grinding is too fine; and (3) the lead concentrate contains high zinc, and the lead and zinc recovery is affected. SUMMARY

[0005] To solve or partially solve the problems in the prior art, the application provides a grinding and separation method for fine-grained lead-zinc ore.

[0006] The application provides a grinding and separation method for fine-grained lead-zinc ore, which comprises the following steps: step S1, re-fine grinding; step S2, pulp preparation and reagent addition; step S3, primary concentration; step S4, reagent addition; and step S5, secondary concentration. In the step S1, the lead-zinc mixed rough concentrate is finely ground by the Aisan mill to obtain a ground product. In the step S2, zinc sulfate, sodium sulfite, No. 25 black medicine and No. 2 oil are added to the ground product. In the step S3, the ground product with the added reagents is concentrated by the first micro-bubble flotation machine to obtain a concentrate 1 and a middling 1. In the step S4, zinc sulfate and sodium sulfite are added to the concentrate 1 obtained in the step S3. In the step S5, the product obtained in the step S4 is concentrated again by the second micro-bubble flotation machine to obtain a lead concentrate and a middling 2, and the middling 1 and the middling 2 are returned to the lead rough concentration operation.

[0007] Optionally, in some embodiments, the Aisan mill has a feed size of +200 mesh not greater than 50%, a grinding concentration of 30-45%, and a lead-zinc monomer liberation degree of the ground product of more than 85%.

[0008] Optionally, in some embodiments, the Aisan mill adjusts the mill speed to ensure that the ground product has a qualified particle size, so that the fineness of the ground product is 90-95% of -500 mesh, and the particle size of -1250 mesh is not greater than 30%.

[0009] Optionally, in some embodiments, the micro-bubble flotation machine has a flotation concentration of 20-30%.

[0010] The technical scheme provided by the application can have the following beneficial effects: The application provides a grinding and separation method for fine-grained lead-zinc ore, which fully utilizes the selective grinding of the Aisan mill to achieve fine grinding and the advantages of the micro-bubble jet flotation machine in the concentration of fine-grained ore, solves the problems of difficult fine grinding in conventional grinding and difficult flotation of fine particles in conventional flotation, and has the advantages of process environmental protection, high separation efficiency, low grinding and separation cost, strong adaptability to fluctuations in ore properties, and improved lead and zinc metal recovery rate.

[0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0012] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout and in which:

[0013] Figure 1 is a flowchart of a grinding separation method of a fine-grained lead-zinc ore according to an embodiment of the present application; DETAILED DESCRIPTION Embodiments of the present application will be described herein below with reference to the accompanying drawings. While the embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0014] It is to be understood that although the terms "first", "second", etc. can be employed in this application to describe various information, these information should not be limited to these terms. These terms are only used to differentiate one piece of information from another piece of information. For example, without departing from the scope of the present application, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0015] In the description of the present application, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0016] Unless otherwise defined, the terms "mounting", "connected", "connecting", "fixed", and the like are to be construed in their broadest sense, for example, they can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements, or interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0017] To solve the above problems, the embodiment of the present application provides a grinding and separation method for fine-grained lead-zinc ore, which can fully utilize the selective grinding of sand mill to achieve fine grinding, and the advantages of micro-bubble jet flotation machine suitable for fine-grained ore separation, to solve the problems of conventional grinding and fine grinding difficulty and conventional flotation of fine particles. The fine grinding and separation process has the advantages of environmental protection, high separation efficiency, low grinding and separation cost, strong adaptability to ore property fluctuation, and the like, and improves the recovery rate of lead and zinc metal.

[0018] The technical solutions of the embodiments of the present application are described in detail below with reference to the drawings.

[0019] Figure 1 is a flowchart of a grinding and separation method for fine-grained lead-zinc ore according to an embodiment of the present application.

[0020] Referring to Figure 1 The grinding and separation method for fine-grained lead-zinc ore according to the embodiment 1 includes the following steps: step S1: fine grinding again; in step S1, the lead-zinc mixed rough concentrate is finely ground by the sand mill, and the grinding product is produced. From the production main flow (i.e. the comparative example), 2m3 / h of ore pulp is extracted from the lead rough selection foam tank lead-zinc mixed rough concentrate, and is sent to the sand mill in the embodiment small flow stirring barrel by a pressurized pump. The mill speed is adjusted to ensure that the grinding product has a qualified particle size (-500 mesh 85%). The sand mill can effectively improve the fine grinding effect and improve the liberation of mineral particles, thereby solving the problem of serious mineral particle crushing.

[0021] Step S2: slurry preparation and reagent addition; in step S2, zinc sulfate, sodium sulfite, No. 25 black medicine and No. 2 oil are added to the grinding product. The main component of No. 25 black medicine is dimethyl phenol dithiophosphoric acid and cresol, which is a commonly used mineral processing agent in the industry. The main effective component of No. 2 oil is pine oil, which is a commonly used mineral processing frother in the industry. Zinc sulfate and sodium sulfite are depressants, No. 2 oil is a frother, and No. 25 black medicine is a collector. The flotation reagents and grinding products are mixed uniformly in the slurry preparation barrel, and stirred for 3-5 minutes to make the reagents fully act on the surface of the mineral particles.

[0022] Step S3: once cleaning; in step S3, the grinding product to which the reagent is added is cleaned by the first micro-bubble flotation machine, to produce the concentrate 1 and the middling 1, the operation enrichment ratio of lead is controlled in the appropriate range of 1.6-2.2 times, the operation recovery rate is greater than 85%, and a higher enrichment ratio is realized under the condition of ensuring the operation recovery rate.

[0023] Step S4: re-dosing; in step S4, the concentrate 1 produced in step S3 is supplemented with zinc sulfate and sodium sulfite, so as to effectively supplement the reagent required for the re-cleaning of the concentrate 1, avoid the lack of reagent, and ensure that the next step is fully reacted, so as to avoid poor flotation effect.

[0024] Step S5: secondary cleaning; in step S5, the product in step S4 is re-cleaned by the second micro-bubble flotation machine to obtain the lead concentrate and the middling 2, the operation enrichment ratio of lead is controlled in the appropriate range of 1.4-1.8 times, the operation recovery rate is greater than 80%, and the lead concentrate grade of about 65% is easily realized, and then the middling 1 and the middling 2 are combined and returned to the lead roughing operation.

[0025] The feed size of the Ai sand mill is not greater than 50% of +200 mesh, the grinding concentration is 30-45%, and the lead-zinc monomer liberation degree of the grinding product is greater than 85%. Controlling the maximum particle size of the feed and the grinding concentration can effectively improve the fineness of the grinding product, reduce the grinding power consumption, and ensure the lead-zinc monomer liberation degree.

[0026] The Ai sand mill adjusts the mill speed to ensure that the grinding product has a qualified particle size, so that the fineness of the fine grinding product is 90-95% of -500 mesh, and the particle size of -1250 mesh is not greater than 30%. Both the -0.025 mm particle size of 90-95% and the -0.01 mm particle size of not more than 30% are achieved, so as to realize the good effect of narrow particle size grinding.

[0027] The flotation concentration of the micro-bubble flotation machine is 20-30%. The lower the flotation concentration, the higher the concentrate grade, but the operation recovery rate decreases. Therefore, the flotation concentration is preferably controlled in the range of 20-30% to balance the concentrate grade and the operation recovery rate.

[0028] The variables of the examples are as follows: the first group has a processing capacity of 2 m3 / h, and the Ai sand mill has a fineness of 90% of -500 mesh; the second group has a processing capacity of 2 m3 / h, and the Ai sand mill has a fineness of 95% of -500 mesh; the third group has a processing capacity of 1 m3 / h, and the Ai sand mill has a fineness of 90% of -500 mesh; and the fourth group has a processing capacity of 1 m3 / h, and the Ai sand mill has a fineness of 95% of -500 mesh.

[0029] The comparative example is the production of the main production process, and the example is branched from the main production process. The comparative example and the example are synchronized.

[0030] The specific operation of the comparative example is as follows: (1) The raw ore is ground and classified in one stage, the grinding product fineness is 85% of -200 mesh, the pulp concentration is 34%, after adding inhibitors and collectors, the slurry is fed into the lead roughing and scavenging, the lead roughing operation produces lead-zinc mixed rough concentrate, which is fed into the lead cleaning, and the lead scavenging tailings are fed into the zinc flotation; (2) The lead-zinc mixed rough concentrate is fed into the lead cleaning after adding zinc sulfate and sodium sulfite, the foam produced by the lead cleaning is fed into the lead cleaning two, the foam produced by the lead cleaning two is fed into the lead cleaning three, and then the final lead concentrate is produced; the tailings of the lead cleaning one are returned to the cyclone classifier by the slurry pump, the coarse particles are returned to the ball mill for regrinding, and the fine particles are fed into the lead roughing operation; the middlings of the lead cleaning two and the cleaning three are returned to the previous operation in sequence.

[0031] Table 1 Test results The results of the examples and the comparative examples show that the Aishaba grinding + twice fine lead micro-bubble cleaning process can effectively replace the conventional three times cleaning + middlings returning and regrinding process, and the lead operation recovery rate is higher than that of the conventional process, the zinc content in the lead concentrate is lower, the zinc loss in the lead concentrate is lower, which shows that the new process is more suitable for the grinding and cleaning of micro-fine particle embedded lead-zinc ore, and realizes the purpose of environmental protection and efficient recovery of valuable galena and sphalerite.

[0032] The above has described various embodiments of the present application, the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles, practical applications or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A method for the attrition scrubbing separation of fine particles of lead and zinc ores, involving regrinding and rebeneficiation of a lead-zinc bulk concentrate, characterized in that: The grinding and separation method of the micro-fine particle lead-zinc ore comprises the following steps: S1: regrinding: regrinding the lead-zinc mixed rough concentrate by an Aixi mill to obtain a grinding product; S2: pulp conditioning and reagent adding: adding zinc sulfate, sodium sulfite, No. 25 black medicine and No. 2 oil into the grinding product obtained in step S1; S3: primary concentration: feeding the slurry obtained in step S2 into a first micro-bubble flotation machine for primary concentration to obtain a lead concentrate 1 and a middling 1; S4: reagent adding: adding zinc sulfate and sodium sulfite into the lead concentrate 1 obtained in step S3; S5: secondary concentration: feeding the slurry obtained in step S4 into a second micro-bubble flotation machine for secondary concentration to obtain a lead concentrate and a middling 2, and feeding the middling 2 and the middling 1 obtained in step S3 back to a lead rough concentration operation.

2. The process for the attrition scrubbing separation of fine particles of lead-zinc ores according to claim 1, characterized in that: In step S1, the Aixi mill has a feeding particle size of +200 mesh not more than 50%, a grinding concentration of 30-45%, and a lead-zinc single liberation degree of more than 85%.

3. The process for the attrition scrubbing separation of fine particles of lead-zinc ores according to claim 1, characterized in that: In step S1, the Aixi mill adjusts the mill speed to ensure that the grinding product has a qualified particle size, so that the fineness of the regrinding product is 90-95% of-500 mesh, and the-1250 mesh particle level is not more than 30%.

4. The process for the attrition scrubbing separation of fine particles of lead-zinc ores according to claim 1, characterized in that: In steps S3 and S5, the flotation concentration of the micro-bubble flotation machine is 20-30%.

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